/* LzmaDec.c -- LZMA Decoder
2021-04-01 : Igor Pavlov : Public domain */

#include "Precomp.h"

#include <string.h>

/* #include "CpuArch.h" */
#include "LzmaDec.h"

#define kNumTopBits 24
#define kTopValue ((UInt32)1 << kNumTopBits)

#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)

#define RC_INIT_SIZE 5

#ifndef _LZMA_DEC_OPT

#define kNumMoveBits 5
#define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }

#define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)
#define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
#define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
#define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
  { UPDATE_0(p); i = (i + i); A0; } else \
  { UPDATE_1(p); i = (i + i) + 1; A1; }

#define TREE_GET_BIT(probs, i) { GET_BIT2(probs + i, i, ;, ;); }

#define REV_BIT(p, i, A0, A1) IF_BIT_0(p + i) \
  { UPDATE_0(p + i); A0; } else \
  { UPDATE_1(p + i); A1; }
#define REV_BIT_VAR(  p, i, m) REV_BIT(p, i, i += m; m += m, m += m; i += m; )
#define REV_BIT_CONST(p, i, m) REV_BIT(p, i, i += m;       , i += m * 2; )
#define REV_BIT_LAST( p, i, m) REV_BIT(p, i, i -= m        , ; )

#define TREE_DECODE(probs, limit, i) \
  { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }

/* #define _LZMA_SIZE_OPT */

#ifdef _LZMA_SIZE_OPT
#define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
#else
#define TREE_6_DECODE(probs, i) \
  { i = 1; \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  i -= 0x40; }
#endif

#define NORMAL_LITER_DEC TREE_GET_BIT(prob, symbol)
#define MATCHED_LITER_DEC \
  matchByte += matchByte; \
  bit = offs; \
  offs &= matchByte; \
  probLit = prob + (offs + bit + symbol); \
  GET_BIT2(probLit, symbol, offs ^= bit; , ;)

#endif // _LZMA_DEC_OPT


#define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_INPUT_EOF; range <<= 8; code = (code << 8) | (*buf++); }

#define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)
#define UPDATE_0_CHECK range = bound;
#define UPDATE_1_CHECK range -= bound; code -= bound;
#define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
  { UPDATE_0_CHECK; i = (i + i); A0; } else \
  { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
#define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
#define TREE_DECODE_CHECK(probs, limit, i) \
  { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }


#define REV_BIT_CHECK(p, i, m) IF_BIT_0_CHECK(p + i) \
  { UPDATE_0_CHECK; i += m; m += m; } else \
  { UPDATE_1_CHECK; m += m; i += m; }


#define kNumPosBitsMax 4
#define kNumPosStatesMax (1 << kNumPosBitsMax)

#define kLenNumLowBits 3
#define kLenNumLowSymbols (1 << kLenNumLowBits)
#define kLenNumHighBits 8
#define kLenNumHighSymbols (1 << kLenNumHighBits)

#define LenLow 0
#define LenHigh (LenLow + 2 * (kNumPosStatesMax << kLenNumLowBits))
#define kNumLenProbs (LenHigh + kLenNumHighSymbols)

#define LenChoice LenLow
#define LenChoice2 (LenLow + (1 << kLenNumLowBits))

#define kNumStates 12
#define kNumStates2 16
#define kNumLitStates 7

#define kStartPosModelIndex 4
#define kEndPosModelIndex 14
#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))

#define kNumPosSlotBits 6
#define kNumLenToPosStates 4

#define kNumAlignBits 4
#define kAlignTableSize (1 << kNumAlignBits)

#define kMatchMinLen 2
#define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols * 2 + kLenNumHighSymbols)

#define kMatchSpecLen_Error_Data (1 << 9)
#define kMatchSpecLen_Error_Fail (kMatchSpecLen_Error_Data - 1)

/* External ASM code needs same CLzmaProb array layout. So don't change it. */

/* (probs_1664) is faster and better for code size at some platforms */
/*
#ifdef MY_CPU_X86_OR_AMD64
*/
#define kStartOffset 1664
#define GET_PROBS p->probs_1664
/*
#define GET_PROBS p->probs + kStartOffset
#else
#define kStartOffset 0
#define GET_PROBS p->probs
#endif
*/

#define SpecPos (-kStartOffset)
#define IsRep0Long (SpecPos + kNumFullDistances)
#define RepLenCoder (IsRep0Long + (kNumStates2 << kNumPosBitsMax))
#define LenCoder (RepLenCoder + kNumLenProbs)
#define IsMatch (LenCoder + kNumLenProbs)
#define Align (IsMatch + (kNumStates2 << kNumPosBitsMax))
#define IsRep (Align + kAlignTableSize)
#define IsRepG0 (IsRep + kNumStates)
#define IsRepG1 (IsRepG0 + kNumStates)
#define IsRepG2 (IsRepG1 + kNumStates)
#define PosSlot (IsRepG2 + kNumStates)
#define Literal (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
#define NUM_BASE_PROBS (Literal + kStartOffset)

#if Align != 0 && kStartOffset != 0
#error Stop_Compiling_Bad_LZMA_kAlign
#endif

#if NUM_BASE_PROBS != 1984
#error Stop_Compiling_Bad_LZMA_PROBS
#endif


#define LZMA_LIT_SIZE 0x300

#define LzmaProps_GetNumProbs(p) (NUM_BASE_PROBS + ((UInt32)LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))


#define CALC_POS_STATE(processedPos, pbMask) (((processedPos) & (pbMask)) << 4)
#define COMBINED_PS_STATE (posState + state)
#define GET_LEN_STATE (posState)

#define LZMA_DIC_MIN (1 << 12)

/*
p->remainLen : shows status of LZMA decoder:
	< kMatchSpecLenStart  : the number of bytes to be copied with (p->rep0) offset
	= kMatchSpecLenStart  : the LZMA stream was finished with end mark
	= kMatchSpecLenStart + 1  : need init range coder
	= kMatchSpecLenStart + 2  : need init range coder and state
	= kMatchSpecLen_Error_Fail                : Internal Code Failure
	= kMatchSpecLen_Error_Data + [0 ... 273]  : LZMA Data Error
*/

/* ---------- LZMA_DECODE_REAL ---------- */
/*
LzmaDec_DecodeReal_3() can be implemented in external ASM file.
3 - is the code compatibility version of that function for check at link time.
*/

#define LZMA_DECODE_REAL LzmaDec_DecodeReal_3

/*
LZMA_DECODE_REAL()
In:
  RangeCoder is normalized
  if (p->dicPos == limit)
  {
	LzmaDec_TryDummy() was called before to exclude LITERAL and MATCH-REP cases.
	So first symbol can be only MATCH-NON-REP. And if that MATCH-NON-REP symbol
	is not END_OF_PAYALOAD_MARKER, then the function doesn't write any byte to dictionary,
	the function returns SZ_OK, and the caller can use (p->remainLen) and (p->reps[0]) later.
  }

Processing:
  The first LZMA symbol will be decoded in any case.
  All main checks for limits are at the end of main loop,
  It decodes additional LZMA-symbols while (p->buf < bufLimit && dicPos < limit),
  RangeCoder is still without last normalization when (p->buf < bufLimit) is being checked.
  But if (p->buf < bufLimit), the caller provided at least (LZMA_REQUIRED_INPUT_MAX + 1) bytes for
  next iteration  before limit (bufLimit + LZMA_REQUIRED_INPUT_MAX),
  that is enough for worst case LZMA symbol with one additional RangeCoder normalization for one bit.
  So that function never reads bufLimit [LZMA_REQUIRED_INPUT_MAX] byte.

Out:
  RangeCoder is normalized
  Result:
	SZ_OK - OK
	  p->remainLen:
		< kMatchSpecLenStart : the number of bytes to be copied with (p->reps[0]) offset
		= kMatchSpecLenStart : the LZMA stream was finished with end mark

	SZ_ERROR_DATA - error, when the MATCH-Symbol refers out of dictionary
	  p->remainLen : undefined
	  p->reps[*]    : undefined
*/


#ifdef _LZMA_DEC_OPT

int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec* p, SizeT limit, const Byte* bufLimit);

#else

static
int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec* p, SizeT limit, const Byte* bufLimit)
{
	CLzmaProb* probs = GET_PROBS;
	unsigned state = (unsigned)p->state;
	UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
	unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
	unsigned lc = p->prop.lc;
	unsigned lpMask = ((unsigned)0x100 << p->prop.lp) - ((unsigned)0x100 >> lc);

	Byte* dic = p->dic;
	SizeT dicBufSize = p->dicBufSize;
	SizeT dicPos = p->dicPos;

	UInt32 processedPos = p->processedPos;
	UInt32 checkDicSize = p->checkDicSize;
	unsigned len = 0;

	const Byte* buf = p->buf;
	UInt32 range = p->range;
	UInt32 code = p->code;

	do
	{
		CLzmaProb* prob;
		UInt32 bound;
		unsigned ttt;
		unsigned posState = CALC_POS_STATE(processedPos, pbMask);

		prob = probs + IsMatch + COMBINED_PS_STATE;
		IF_BIT_0(prob)
		{
			unsigned symbol;
			UPDATE_0(prob);
			prob = probs + Literal;
			if (processedPos != 0 || checkDicSize != 0)
				prob += (UInt32)3 * ((((processedPos << 8) + dic[(dicPos == 0 ? dicBufSize : dicPos) - 1]) & lpMask) << lc);
			processedPos++;

			if (state < kNumLitStates)
			{
				state -= (state < 4) ? state : 3;
				symbol = 1;
#ifdef _LZMA_SIZE_OPT
				do { NORMAL_LITER_DEC } while (symbol < 0x100);
#else
				NORMAL_LITER_DEC
					NORMAL_LITER_DEC
					NORMAL_LITER_DEC
					NORMAL_LITER_DEC
					NORMAL_LITER_DEC
					NORMAL_LITER_DEC
					NORMAL_LITER_DEC
					NORMAL_LITER_DEC
#endif
			}
			else
			{
				unsigned matchByte = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
				unsigned offs = 0x100;
				state -= (state < 10) ? 3 : 6;
				symbol = 1;
#ifdef _LZMA_SIZE_OPT
				do
				{
					unsigned bit;
					CLzmaProb* probLit;
					MATCHED_LITER_DEC
				} while (symbol < 0x100);
#else
					{
						unsigned bit;
						CLzmaProb* probLit;
						MATCHED_LITER_DEC
							MATCHED_LITER_DEC
							MATCHED_LITER_DEC
							MATCHED_LITER_DEC
							MATCHED_LITER_DEC
							MATCHED_LITER_DEC
							MATCHED_LITER_DEC
							MATCHED_LITER_DEC
					}
#endif
			}

			dic[dicPos++] = (Byte)symbol;
			continue;
		}

		{
			UPDATE_1(prob);
			prob = probs + IsRep + state;
			IF_BIT_0(prob)
			{
				UPDATE_0(prob);
				state += kNumStates;
				prob = probs + LenCoder;
			}
	  else
	  {
	  UPDATE_1(prob);
	  prob = probs + IsRepG0 + state;
	  IF_BIT_0(prob)
	  {
		  UPDATE_0(prob);
		  prob = probs + IsRep0Long + COMBINED_PS_STATE;
		  IF_BIT_0(prob)
		  {
			  UPDATE_0(prob);

			  // that case was checked before with kBadRepCode
			  // if (checkDicSize == 0 && processedPos == 0) { len = kMatchSpecLen_Error_Data + 1; break; }
			  // The caller doesn't allow (dicPos == limit) case here
			  // so we don't need the following check:
			  // if (dicPos == limit) { state = state < kNumLitStates ? 9 : 11; len = 1; break; }

			  dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
			  dicPos++;
			  processedPos++;
			  state = state < kNumLitStates ? 9 : 11;
			  continue;
		  }
		  UPDATE_1(prob);
	  }
		else
		{
		UInt32 distance;
		UPDATE_1(prob);
		prob = probs + IsRepG1 + state;
		IF_BIT_0(prob)
		{
			UPDATE_0(prob);
			distance = rep1;
		}
		  else
		  {
		  UPDATE_1(prob);
		  prob = probs + IsRepG2 + state;
		  IF_BIT_0(prob)
		  {
			  UPDATE_0(prob);
			  distance = rep2;
		  }
			else
			{
			UPDATE_1(prob);
			distance = rep3;
			rep3 = rep2;
			}
			rep2 = rep1;
		  }
		  rep1 = rep0;
		  rep0 = distance;
		}
		state = state < kNumLitStates ? 8 : 11;
		prob = probs + RepLenCoder;
	  }

#ifdef _LZMA_SIZE_OPT
	  {
	  unsigned lim, offset;
	  CLzmaProb* probLen = prob + LenChoice;
	  IF_BIT_0(probLen)
	  {
		  UPDATE_0(probLen);
		  probLen = prob + LenLow + GET_LEN_STATE;
		  offset = 0;
		  lim = (1 << kLenNumLowBits);
	  }
		else
		{
		UPDATE_1(probLen);
		probLen = prob + LenChoice2;
		IF_BIT_0(probLen)
		{
			UPDATE_0(probLen);
			probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
			offset = kLenNumLowSymbols;
			lim = (1 << kLenNumLowBits);
		}
		  else
		  {
		  UPDATE_1(probLen);
		  probLen = prob + LenHigh;
		  offset = kLenNumLowSymbols * 2;
		  lim = (1 << kLenNumHighBits);
		  }
		}
		TREE_DECODE(probLen, lim, len);
		len += offset;
	  }
#else
	  {
		  CLzmaProb* probLen = prob + LenChoice;
		  IF_BIT_0(probLen)
		  {
			  UPDATE_0(probLen);
			  probLen = prob + LenLow + GET_LEN_STATE;
			  len = 1;
			  TREE_GET_BIT(probLen, len);
			  TREE_GET_BIT(probLen, len);
			  TREE_GET_BIT(probLen, len);
			  len -= 8;
		  }
		else
		{
		UPDATE_1(probLen);
		probLen = prob + LenChoice2;
		IF_BIT_0(probLen)
		{
			UPDATE_0(probLen);
			probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
			len = 1;
			TREE_GET_BIT(probLen, len);
			TREE_GET_BIT(probLen, len);
			TREE_GET_BIT(probLen, len);
		}
		  else
		  {
		  UPDATE_1(probLen);
		  probLen = prob + LenHigh;
		  TREE_DECODE(probLen, (1 << kLenNumHighBits), len);
		  len += kLenNumLowSymbols * 2;
		  }
		}
	  }
#endif

	  if (state >= kNumStates)
	  {
		  UInt32 distance;
		  prob = probs + PosSlot +
			  ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
		  TREE_6_DECODE(prob, distance);
		  if (distance >= kStartPosModelIndex)
		  {
			  unsigned posSlot = (unsigned)distance;
			  unsigned numDirectBits = (unsigned)(((distance >> 1) - 1));
			  distance = (2 | (distance & 1));
			  if (posSlot < kEndPosModelIndex)
			  {
				  distance <<= numDirectBits;
				  prob = probs + SpecPos;
				  {
					  UInt32 m = 1;
					  distance++;
					  do
					  {
						  REV_BIT_VAR(prob, distance, m);
					  } while (--numDirectBits);
					  distance -= m;
				  }
			  }
			  else
			  {
				  numDirectBits -= kNumAlignBits;
				  do
				  {
					  NORMALIZE
						  range >>= 1;

					  {
						  UInt32 t;
						  code -= range;
						  t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
						  distance = (distance << 1) + (t + 1);
						  code += range & t;
					  }
					  /*
					  distance <<= 1;
					  if (code >= range)
					  {
						code -= range;
						distance |= 1;
					  }
					  */
				  } while (--numDirectBits);
				  prob = probs + Align;
				  distance <<= kNumAlignBits;
				  {
					  unsigned i = 1;
					  REV_BIT_CONST(prob, i, 1);
					  REV_BIT_CONST(prob, i, 2);
					  REV_BIT_CONST(prob, i, 4);
					  REV_BIT_LAST(prob, i, 8);
					  distance |= i;
				  }
				  if (distance == (UInt32)0xFFFFFFFF)
				  {
					  len = kMatchSpecLenStart;
					  state -= kNumStates;
					  break;
				  }
			  }
		  }

		  rep3 = rep2;
		  rep2 = rep1;
		  rep1 = rep0;
		  rep0 = distance + 1;
		  state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
		  if (distance >= (checkDicSize == 0 ? processedPos : checkDicSize))
		  {
			  len += kMatchSpecLen_Error_Data + kMatchMinLen;
			  // len = kMatchSpecLen_Error_Data;
			  // len += kMatchMinLen;
			  break;
		  }
	  }

	  len += kMatchMinLen;

	  {
		  SizeT rem;
		  unsigned curLen;
		  SizeT pos;

		  if ((rem = limit - dicPos) == 0)
		  {
			  /*
			  We stop decoding and return SZ_OK, and we can resume decoding later.
			  Any error conditions can be tested later in caller code.
			  For more strict mode we can stop decoding with error
			  // len += kMatchSpecLen_Error_Data;
			  */
			  break;
		  }

		  curLen = ((rem < len) ? (unsigned)rem : len);
		  pos = dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0);

		  processedPos += (UInt32)curLen;

		  len -= curLen;
		  if (curLen <= dicBufSize - pos)
		  {
			  Byte* dest = dic + dicPos;
			  ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
			  const Byte* lim = dest + curLen;
			  dicPos += (SizeT)curLen;
			  do
				  *(dest) = (Byte) * (dest + src);
			  while (++dest != lim);
		  }
		  else
		  {
			  do
			  {
				  dic[dicPos++] = dic[pos];
				  if (++pos == dicBufSize)
					  pos = 0;
			  } while (--curLen != 0);
		  }
	  }
		}
	} while (dicPos < limit && buf < bufLimit);

	NORMALIZE;

	p->buf = buf;
	p->range = range;
	p->code = code;
	p->remainLen = (UInt32)len; // & (kMatchSpecLen_Error_Data - 1); // we can write real length for error matches too.
	p->dicPos = dicPos;
	p->processedPos = processedPos;
	p->reps[0] = rep0;
	p->reps[1] = rep1;
	p->reps[2] = rep2;
	p->reps[3] = rep3;
	p->state = (UInt32)state;
	if (len >= kMatchSpecLen_Error_Data)
		return SZ_ERROR_DATA;
	return SZ_OK;
}
#endif



static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec* p, SizeT limit)
{
	unsigned len = (unsigned)p->remainLen;
	if (len == 0 /* || len >= kMatchSpecLenStart */)
		return;
	{
		SizeT dicPos = p->dicPos;
		Byte* dic;
		SizeT dicBufSize;
		SizeT rep0;   /* we use SizeT to avoid the BUG of VC14 for AMD64 */
		{
			SizeT rem = limit - dicPos;
			if (rem < len)
			{
				len = (unsigned)(rem);
				if (len == 0)
					return;
			}
		}

		if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
			p->checkDicSize = p->prop.dicSize;

		p->processedPos += (UInt32)len;
		p->remainLen -= (UInt32)len;
		dic = p->dic;
		rep0 = p->reps[0];
		dicBufSize = p->dicBufSize;
		do
		{
			dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
			dicPos++;
		} while (--len);
		p->dicPos = dicPos;
	}
}


/*
At staring of new stream we have one of the following symbols:
  - Literal        - is allowed
  - Non-Rep-Match  - is allowed only if it's end marker symbol
  - Rep-Match      - is not allowed
We use early check of (RangeCoder:Code) over kBadRepCode to simplify main decoding code
*/

#define kRange0 0xFFFFFFFF
#define kBound0 ((kRange0 >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1))
#define kBadRepCode (kBound0 + (((kRange0 - kBound0) >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1)))
#if kBadRepCode != (0xC0000000 - 0x400)
#error Stop_Compiling_Bad_LZMA_Check
#endif


/*
LzmaDec_DecodeReal2():
  It calls LZMA_DECODE_REAL() and it adjusts limit according (p->checkDicSize).

We correct (p->checkDicSize) after LZMA_DECODE_REAL() and in LzmaDec_WriteRem(),
and we support the following state of (p->checkDicSize):
  if (total_processed < p->prop.dicSize) then
  {
	(total_processed == p->processedPos)
	(p->checkDicSize == 0)
  }
  else
	(p->checkDicSize == p->prop.dicSize)
*/

static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec* p, SizeT limit, const Byte* bufLimit)
{
	if (p->checkDicSize == 0)
	{
		UInt32 rem = p->prop.dicSize - p->processedPos;
		if (limit - p->dicPos > rem)
			limit = p->dicPos + rem;
	}
	{
		int res = LZMA_DECODE_REAL(p, limit, bufLimit);
		if (p->checkDicSize == 0 && p->processedPos >= p->prop.dicSize)
			p->checkDicSize = p->prop.dicSize;
		return res;
	}
}



typedef enum
{
	DUMMY_INPUT_EOF, /* need more input data */
	DUMMY_LIT,
	DUMMY_MATCH,
	DUMMY_REP
} ELzmaDummy;


#define IS_DUMMY_END_MARKER_POSSIBLE(dummyRes) ((dummyRes) == DUMMY_MATCH)

static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec* p, const Byte* buf, const Byte** bufOut)
{
	UInt32 range = p->range;
	UInt32 code = p->code;
	const Byte* bufLimit = *bufOut;
	const CLzmaProb* probs = GET_PROBS;
	unsigned state = (unsigned)p->state;
	ELzmaDummy res;

	for (;;)
	{
		const CLzmaProb* prob;
		UInt32 bound;
		unsigned ttt;
		unsigned posState = CALC_POS_STATE(p->processedPos, ((unsigned)1 << p->prop.pb) - 1);

		prob = probs + IsMatch + COMBINED_PS_STATE;
		IF_BIT_0_CHECK(prob)
		{
			UPDATE_0_CHECK

				prob = probs + Literal;
			if (p->checkDicSize != 0 || p->processedPos != 0)
				prob += ((UInt32)LZMA_LIT_SIZE *
					((((p->processedPos) & (((unsigned)1 << (p->prop.lp)) - 1)) << p->prop.lc) +
						((unsigned)p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));

			if (state < kNumLitStates)
			{
				unsigned symbol = 1;
				do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
			}
			else
			{
				unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
					(p->dicPos < p->reps[0] ? p->dicBufSize : 0)];
				unsigned offs = 0x100;
				unsigned symbol = 1;
				do
				{
					unsigned bit;
					const CLzmaProb* probLit;
					matchByte += matchByte;
					bit = offs;
					offs &= matchByte;
					probLit = prob + (offs + bit + symbol);
					GET_BIT2_CHECK(probLit, symbol, offs ^= bit;, ; )
				} while (symbol < 0x100);
			}
			res = DUMMY_LIT;
		}
	else
	{
	unsigned len;
	UPDATE_1_CHECK;

	prob = probs + IsRep + state;
	IF_BIT_0_CHECK(prob)
	{
		UPDATE_0_CHECK;
		state = 0;
		prob = probs + LenCoder;
		res = DUMMY_MATCH;
	}
	  else
	  {
	  UPDATE_1_CHECK;
	  res = DUMMY_REP;
	  prob = probs + IsRepG0 + state;
	  IF_BIT_0_CHECK(prob)
	  {
		  UPDATE_0_CHECK;
		  prob = probs + IsRep0Long + COMBINED_PS_STATE;
		  IF_BIT_0_CHECK(prob)
		  {
			  UPDATE_0_CHECK;
			  break;
		  }
		  else
		  {
		  UPDATE_1_CHECK;
		  }
	  }
		else
		{
		UPDATE_1_CHECK;
		prob = probs + IsRepG1 + state;
		IF_BIT_0_CHECK(prob)
		{
			UPDATE_0_CHECK;
		}
		  else
		  {
		  UPDATE_1_CHECK;
		  prob = probs + IsRepG2 + state;
		  IF_BIT_0_CHECK(prob)
		  {
			  UPDATE_0_CHECK;
		  }
			else
			{
			UPDATE_1_CHECK;
			}
		  }
		}
		state = kNumStates;
		prob = probs + RepLenCoder;
	  }
	  {
	  unsigned limit, offset;
	  const CLzmaProb* probLen = prob + LenChoice;
	  IF_BIT_0_CHECK(probLen)
	  {
		  UPDATE_0_CHECK;
		  probLen = prob + LenLow + GET_LEN_STATE;
		  offset = 0;
		  limit = 1 << kLenNumLowBits;
	  }
		else
		{
		UPDATE_1_CHECK;
		probLen = prob + LenChoice2;
		IF_BIT_0_CHECK(probLen)
		{
			UPDATE_0_CHECK;
			probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
			offset = kLenNumLowSymbols;
			limit = 1 << kLenNumLowBits;
		}
		  else
		  {
		  UPDATE_1_CHECK;
		  probLen = prob + LenHigh;
		  offset = kLenNumLowSymbols * 2;
		  limit = 1 << kLenNumHighBits;
		  }
		}
		TREE_DECODE_CHECK(probLen, limit, len);
		len += offset;
	  }

	  if (state < 4)
	  {
		  unsigned posSlot;
		  prob = probs + PosSlot +
			  ((len < kNumLenToPosStates - 1 ? len : kNumLenToPosStates - 1) <<
				  kNumPosSlotBits);
		  TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
		  if (posSlot >= kStartPosModelIndex)
		  {
			  unsigned numDirectBits = ((posSlot >> 1) - 1);

			  if (posSlot < kEndPosModelIndex)
			  {
				  prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits);
			  }
			  else
			  {
				  numDirectBits -= kNumAlignBits;
				  do
				  {
					  NORMALIZE_CHECK
						  range >>= 1;
					  code -= range & (((code - range) >> 31) - 1);
					  /* if (code >= range) code -= range; */
				  } while (--numDirectBits);
				  prob = probs + Align;
				  numDirectBits = kNumAlignBits;
			  }
			  {
				  unsigned i = 1;
				  unsigned m = 1;
				  do
				  {
					  REV_BIT_CHECK(prob, i, m);
				  } while (--numDirectBits);
			  }
		  }
	  }
	}
	break;
	}
	NORMALIZE_CHECK;

	*bufOut = buf;
	return res;
}

void LzmaDec_InitDicAndState(CLzmaDec* p, BoolInt initDic, BoolInt initState);
void LzmaDec_InitDicAndState(CLzmaDec* p, BoolInt initDic, BoolInt initState)
{
	p->remainLen = kMatchSpecLenStart + 1;
	p->tempBufSize = 0;

	if (initDic)
	{
		p->processedPos = 0;
		p->checkDicSize = 0;
		p->remainLen = kMatchSpecLenStart + 2;
	}
	if (initState)
		p->remainLen = kMatchSpecLenStart + 2;
}

void LzmaDec_Init(CLzmaDec* p)
{
	p->dicPos = 0;
	LzmaDec_InitDicAndState(p, True, True);
}


/*
LZMA supports optional end_marker.
So the decoder can lookahead for one additional LZMA-Symbol to check end_marker.
That additional LZMA-Symbol can require up to LZMA_REQUIRED_INPUT_MAX bytes in input stream.
When the decoder reaches dicLimit, it looks (finishMode) parameter:
  if (finishMode == LZMA_FINISH_ANY), the decoder doesn't lookahead
  if (finishMode != LZMA_FINISH_ANY), the decoder lookahead, if end_marker is possible for current position

When the decoder lookahead, and the lookahead symbol is not end_marker, we have two ways:
  1) Strict mode (default) : the decoder returns SZ_ERROR_DATA.
  2) The relaxed mode (alternative mode) : we could return SZ_OK, and the caller
	 must check (status) value. The caller can show the error,
	 if the end of stream is expected, and the (status) is noit
	 LZMA_STATUS_FINISHED_WITH_MARK or LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK.
*/


#define RETURN__NOT_FINISHED__FOR_FINISH \
  *status = LZMA_STATUS_NOT_FINISHED; \
  return SZ_ERROR_DATA; // for strict mode
// return SZ_OK; // for relaxed mode


SRes LzmaDec_DecodeToDic(CLzmaDec* p, SizeT dicLimit, const Byte* src, SizeT* srcLen,
	ELzmaFinishMode finishMode, ELzmaStatus* status)
{
	SizeT inSize = *srcLen;
	(*srcLen) = 0;
	*status = LZMA_STATUS_NOT_SPECIFIED;

	if (p->remainLen > kMatchSpecLenStart)
	{
		if (p->remainLen > kMatchSpecLenStart + 2)
			return p->remainLen == kMatchSpecLen_Error_Fail ? SZ_ERROR_FAIL : SZ_ERROR_DATA;

		for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
			p->tempBuf[p->tempBufSize++] = *src++;
		if (p->tempBufSize != 0 && p->tempBuf[0] != 0)
			return SZ_ERROR_DATA;
		if (p->tempBufSize < RC_INIT_SIZE)
		{
			*status = LZMA_STATUS_NEEDS_MORE_INPUT;
			return SZ_OK;
		}
		p->code =
			((UInt32)p->tempBuf[1] << 24)
			| ((UInt32)p->tempBuf[2] << 16)
			| ((UInt32)p->tempBuf[3] << 8)
			| ((UInt32)p->tempBuf[4]);

		if (p->checkDicSize == 0
			&& p->processedPos == 0
			&& p->code >= kBadRepCode)
			return SZ_ERROR_DATA;

		p->range = 0xFFFFFFFF;
		p->tempBufSize = 0;

		if (p->remainLen > kMatchSpecLenStart + 1)
		{
			SizeT numProbs = LzmaProps_GetNumProbs(&p->prop);
			SizeT i;
			CLzmaProb* probs = p->probs;
			for (i = 0; i < numProbs; i++)
				probs[i] = kBitModelTotal >> 1;
			p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
			p->state = 0;
		}

		p->remainLen = 0;
	}

	for (;;)
	{
		if (p->remainLen == kMatchSpecLenStart)
		{
			if (p->code != 0)
				return SZ_ERROR_DATA;
			*status = LZMA_STATUS_FINISHED_WITH_MARK;
			return SZ_OK;
		}

		LzmaDec_WriteRem(p, dicLimit);

		{
			// (p->remainLen == 0 || p->dicPos == dicLimit)

			int checkEndMarkNow = 0;

			if (p->dicPos >= dicLimit)
			{
				if (p->remainLen == 0 && p->code == 0)
				{
					*status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
					return SZ_OK;
				}
				if (finishMode == LZMA_FINISH_ANY)
				{
					*status = LZMA_STATUS_NOT_FINISHED;
					return SZ_OK;
				}
				if (p->remainLen != 0)
				{
					RETURN__NOT_FINISHED__FOR_FINISH;
				}
				checkEndMarkNow = 1;
			}

			// (p->remainLen == 0)

			if (p->tempBufSize == 0)
			{
				const Byte* bufLimit;
				int dummyProcessed = -1;

				if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
				{
					const Byte* bufOut = src + inSize;

					ELzmaDummy dummyRes = LzmaDec_TryDummy(p, src, &bufOut);

					if (dummyRes == DUMMY_INPUT_EOF)
					{
						size_t i;
						if (inSize >= LZMA_REQUIRED_INPUT_MAX)
							break;
						(*srcLen) += inSize;
						p->tempBufSize = (unsigned)inSize;
						for (i = 0; i < inSize; i++)
							p->tempBuf[i] = src[i];
						*status = LZMA_STATUS_NEEDS_MORE_INPUT;
						return SZ_OK;
					}

					dummyProcessed = (int)(bufOut - src);
					if ((unsigned)dummyProcessed > LZMA_REQUIRED_INPUT_MAX)
						break;

					if (checkEndMarkNow && !IS_DUMMY_END_MARKER_POSSIBLE(dummyRes))
					{
						unsigned i;
						(*srcLen) += (unsigned)dummyProcessed;
						p->tempBufSize = (unsigned)dummyProcessed;
						for (i = 0; i < (unsigned)dummyProcessed; i++)
							p->tempBuf[i] = src[i];
						// p->remainLen = kMatchSpecLen_Error_Data;
						RETURN__NOT_FINISHED__FOR_FINISH;
					}

					bufLimit = src;
					// we will decode only one iteration
				}
				else
					bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;

				p->buf = src;

				{
					int res = LzmaDec_DecodeReal2(p, dicLimit, bufLimit);

					SizeT processed = (SizeT)(p->buf - src);

					if (dummyProcessed < 0)
					{
						if (processed > inSize)
							break;
					}
					else if ((unsigned)dummyProcessed != processed)
						break;

					src += processed;
					inSize -= processed;
					(*srcLen) += processed;

					if (res != SZ_OK)
					{
						p->remainLen = kMatchSpecLen_Error_Data;
						return SZ_ERROR_DATA;
					}
				}
				continue;
			}

			{
				// we have some data in (p->tempBuf)
				// in strict mode: tempBufSize is not enough for one Symbol decoding.
				// in relaxed mode: tempBufSize not larger than required for one Symbol decoding.

				unsigned rem = p->tempBufSize;
				unsigned ahead = 0;
				int dummyProcessed = -1;

				while (rem < LZMA_REQUIRED_INPUT_MAX && ahead < inSize)
					p->tempBuf[rem++] = src[ahead++];

				// ahead - the size of new data copied from (src) to (p->tempBuf)
				// rem   - the size of temp buffer including new data from (src)

				if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
				{
					const Byte* bufOut = p->tempBuf + rem;

					ELzmaDummy dummyRes = LzmaDec_TryDummy(p, p->tempBuf, &bufOut);

					if (dummyRes == DUMMY_INPUT_EOF)
					{
						if (rem >= LZMA_REQUIRED_INPUT_MAX)
							break;
						p->tempBufSize = rem;
						(*srcLen) += (SizeT)ahead;
						*status = LZMA_STATUS_NEEDS_MORE_INPUT;
						return SZ_OK;
					}

					dummyProcessed = (int)(bufOut - p->tempBuf);

					if ((unsigned)dummyProcessed < p->tempBufSize)
						break;

					if (checkEndMarkNow && !IS_DUMMY_END_MARKER_POSSIBLE(dummyRes))
					{
						(*srcLen) += (unsigned)dummyProcessed - p->tempBufSize;
						p->tempBufSize = (unsigned)dummyProcessed;
						// p->remainLen = kMatchSpecLen_Error_Data;
						RETURN__NOT_FINISHED__FOR_FINISH;
					}
				}

				p->buf = p->tempBuf;

				{
					// we decode one symbol from (p->tempBuf) here, so the (bufLimit) is equal to (p->buf)
					int res = LzmaDec_DecodeReal2(p, dicLimit, p->buf);

					SizeT processed = (SizeT)(p->buf - p->tempBuf);
					rem = p->tempBufSize;

					if (dummyProcessed < 0)
					{
						if (processed > LZMA_REQUIRED_INPUT_MAX)
							break;
						if (processed < rem)
							break;
					}
					else if ((unsigned)dummyProcessed != processed)
						break;

					processed -= rem;

					src += processed;
					inSize -= processed;
					(*srcLen) += processed;
					p->tempBufSize = 0;

					if (res != SZ_OK)
					{
						p->remainLen = kMatchSpecLen_Error_Data;
						return SZ_ERROR_DATA;
					}
				}
			}
		}
	}

	/*  Some unexpected error: internal error of code, memory corruption or hardware failure */
	p->remainLen = kMatchSpecLen_Error_Fail;
	return SZ_ERROR_FAIL;
}



SRes LzmaDec_DecodeToBuf(CLzmaDec* p, Byte* dest, SizeT* destLen, const Byte* src, SizeT* srcLen, ELzmaFinishMode finishMode, ELzmaStatus* status)
{
	SizeT outSize = *destLen;
	SizeT inSize = *srcLen;
	*srcLen = *destLen = 0;
	for (;;)
	{
		SizeT inSizeCur = inSize, outSizeCur, dicPos;
		ELzmaFinishMode curFinishMode;
		SRes res;
		if (p->dicPos == p->dicBufSize)
			p->dicPos = 0;
		dicPos = p->dicPos;
		if (outSize > p->dicBufSize - dicPos)
		{
			outSizeCur = p->dicBufSize;
			curFinishMode = LZMA_FINISH_ANY;
		}
		else
		{
			outSizeCur = dicPos + outSize;
			curFinishMode = finishMode;
		}

		res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
		src += inSizeCur;
		inSize -= inSizeCur;
		*srcLen += inSizeCur;
		outSizeCur = p->dicPos - dicPos;
		memcpy(dest, p->dic + dicPos, outSizeCur);
		dest += outSizeCur;
		outSize -= outSizeCur;
		*destLen += outSizeCur;
		if (res != 0)
			return res;
		if (outSizeCur == 0 || outSize == 0)
			return SZ_OK;
	}
}

void LzmaDec_FreeProbs(CLzmaDec* p, ISzAllocPtr alloc)
{
	ISzAlloc_Free(alloc, p->probs);
	p->probs = NULL;
}

static void LzmaDec_FreeDict(CLzmaDec* p, ISzAllocPtr alloc)
{
	ISzAlloc_Free(alloc, p->dic);
	p->dic = NULL;
}

void LzmaDec_Free(CLzmaDec* p, ISzAllocPtr alloc)
{
	LzmaDec_FreeProbs(p, alloc);
	LzmaDec_FreeDict(p, alloc);
}

SRes LzmaProps_Decode(CLzmaProps* p, const Byte* data, unsigned size)
{
	UInt32 dicSize;
	Byte d;

	if (size < LZMA_PROPS_SIZE)
		return SZ_ERROR_UNSUPPORTED;
	else
		dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);

	if (dicSize < LZMA_DIC_MIN)
		dicSize = LZMA_DIC_MIN;
	p->dicSize = dicSize;

	d = data[0];
	if (d >= (9 * 5 * 5))
		return SZ_ERROR_UNSUPPORTED;

	p->lc = (Byte)(d % 9);
	d /= 9;
	p->pb = (Byte)(d / 5);
	p->lp = (Byte)(d % 5);

	return SZ_OK;
}

static SRes LzmaDec_AllocateProbs2(CLzmaDec* p, const CLzmaProps* propNew, ISzAllocPtr alloc)
{
	UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
	if (!p->probs || numProbs != p->numProbs)
	{
		LzmaDec_FreeProbs(p, alloc);
		p->probs = (CLzmaProb*)ISzAlloc_Alloc(alloc, numProbs * sizeof(CLzmaProb));
		if (!p->probs)
			return SZ_ERROR_MEM;
		p->probs_1664 = p->probs + 1664;
		p->numProbs = numProbs;
	}
	return SZ_OK;
}

SRes LzmaDec_AllocateProbs(CLzmaDec* p, const Byte* props, unsigned propsSize, ISzAllocPtr alloc)
{
	CLzmaProps propNew;
	RINOK(LzmaProps_Decode(&propNew, props, propsSize));
	RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
	p->prop = propNew;
	return SZ_OK;
}

SRes LzmaDec_Allocate(CLzmaDec* p, const Byte* props, unsigned propsSize, ISzAllocPtr alloc)
{
	CLzmaProps propNew;
	SizeT dicBufSize;
	RINOK(LzmaProps_Decode(&propNew, props, propsSize));
	RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));

	{
		UInt32 dictSize = propNew.dicSize;
		SizeT mask = ((UInt32)1 << 12) - 1;
		if (dictSize >= ((UInt32)1 << 30)) mask = ((UInt32)1 << 22) - 1;
		else if (dictSize >= ((UInt32)1 << 22)) mask = ((UInt32)1 << 20) - 1;;
		dicBufSize = ((SizeT)dictSize + mask) & ~mask;
		if (dicBufSize < dictSize)
			dicBufSize = dictSize;
	}

	if (!p->dic || dicBufSize != p->dicBufSize)
	{
		LzmaDec_FreeDict(p, alloc);
		p->dic = (Byte*)ISzAlloc_Alloc(alloc, dicBufSize);
		if (!p->dic)
		{
			LzmaDec_FreeProbs(p, alloc);
			return SZ_ERROR_MEM;
		}
	}
	p->dicBufSize = dicBufSize;
	p->prop = propNew;
	return SZ_OK;
}

SRes LzmaDecode(Byte* dest, SizeT* destLen, const Byte* src, SizeT* srcLen,
	const Byte* propData, unsigned propSize, ELzmaFinishMode finishMode,
	ELzmaStatus* status, ISzAllocPtr alloc)
{
	CLzmaDec p;
	SRes res;
	SizeT outSize = *destLen, inSize = *srcLen;
	*destLen = *srcLen = 0;
	*status = LZMA_STATUS_NOT_SPECIFIED;
	if (inSize < RC_INIT_SIZE)
		return SZ_ERROR_INPUT_EOF;
	LzmaDec_Construct(&p);
	RINOK(LzmaDec_AllocateProbs(&p, propData, propSize, alloc));
	p.dic = dest;
	p.dicBufSize = outSize;
	LzmaDec_Init(&p);
	*srcLen = inSize;
	res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
	*destLen = p.dicPos;
	if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
		res = SZ_ERROR_INPUT_EOF;
	LzmaDec_FreeProbs(&p, alloc);
	return res;
}
